142 DUBLIN UNIVKKSITY 



The greater part of the observations were made in company with C. 

 Spence Bate, F. L. S., to whose kindness I am indebted for the identi- 

 fication of most of the amphipodous Crustacea noticed, and most of which 

 were obtained in a dredging excursion in company with him and Dr. 

 Hugh Falconer, the Rev. Mr. Everest, and Dr. Danscy, in the harbour 

 and roads of Plymouth, within the Breakwater, on the 22nd of April 

 last. 



The results afforded deserve to be noted, as the ground is similar in 

 its nature to the ground over which most of my Dublin work has been 

 done, and, therefore, allowing of a comparison being drawn between 

 these two localities. 



The nature of the grounds over which we dredged were as follows : — 



1. Muddy black sand: here we obtained Gebia deltura (one specimen). 

 Ophiocoma bellis, Comatula rosacea, and a few other species. 



2. Shingle free from mud or sand ; from hence the more remarkable 

 species were — Bernhardus Hyndmanni, B. Thompsoni, B. Icevis, B. Cua- 

 nensis, Bernhardus streblonyx, — all, however, except the last, much rarer 

 than in similar grounds in Dublin. 'Inachus Dorsettensis, tolerably com- 

 mon ; Hyas coarctatus, one specimen ; Eurynome aspera, common ; 

 Pilumnus hirtellus, common. Portunus puber and P. depurator, common. 

 P. holsatus, one specimen. Porcellana platycheles, one specimen. P. 

 longicornis, very common. Galathea Andrewsii, common, but rarer than 

 in Dublin. 



• 3. A Zostera bank, called by the boatmen the " Leek Bank." Here, 

 in addition to B. streblonyx, Port, depurator and puber, single specimens 

 of Galathea sauamifera, Crangon vulgaris, and Ilippolyte {Lysippe) Cran- 

 chii, occurred ; and the only Isopod met during the day, Idotea pelagica. 

 We took but one cast of the dredge here. 



4. Ridges of slate, which were perpetually bringing up the dredge, 

 required a long and strong pull to free it. Among these, in addition to 

 Echinidse, we met an old bone containing, safely ensconced within it, 

 a female Portunus arcuatus in spawn. It was impossible to note the 

 localities of the Amphipoda obtained, further than that they were more 

 numerous than in Dublin Bay. 



The following were among the rarities obtained: — Gammarus (?) 

 ftn llidus, G. obtusatus, G. Othonis, and two undescribed species (of which 

 Mr. C. Spence Bate will send an account hereafter), Lembos Websterii, 

 Ampolisca typici's. 



